This invention relates to apparatus and method for movably interconnecting lengths of pipe. More specifically, this invention relates to a ball joint pipe connection for movably interlocking adjacent ends of a pair of pipes in an automotive exhaust system.
In the prior art, a wide variety of pipe connections are well known. Such pipe connections are particularly useful in automotive exhaust systems wherein interconnected pipe networks extend from one or more exhaust gas manifolds through a catalytic converter and/or muffler, and further to the rear of an automotive vehicle. Of particular importance are the variety of exhaust pipe connections which allow for relative movement between interconnected lengths of pipe. That is, it is often necessary in automotive exhaust systems to provide pipe connections which allow relative movement between connected pipes to compensate for the continuous vibrational and torsional forces inherent with an internal combustion engine. Without such relative movement, cracks and leaks in the system tend to develop prematurely to require frequent replacement of system components.
In the past, various schemes such as the use of convoluted piping and spring-loaded flange assemblies have been proposed for compensating for the shakes and vibrations transmitted from an internal combustion engine to an exhaust system. A variety of ball-type pipe joints have also been proposed. See, for example, U.S. Pat. Nos. 3,002,269; 2,318,006; and 2,319,939. However, with modern automotive exhaust systems, it is imperative that all pipe connections are leak free for a prolonged operating life. Further, it is desirable that such pipe connections are quickly and easily formed from inexpensive materials. Pipe connections of the prior art have not satisfactorily fulfilled these needs.
For the most part, automotive manufacturers have heretofore mounted internal combustion engines with their crankshafts extending longitudinally with respect to the vehicle chassis. In this manner, exhaust pipe connections have been primarily required to withstand axial rotation between adjacent pipes together with shaking and vibrating of relatively small magnitude. However, some automotive manufacturers have recently determined that mounting of an engine with its crankshaft extending transversely of the vehicle chassis can be advantageous under certain conditions, particularly for use with front wheel drive systems. Such transversely mounted engines, however, require exhaust pipe connections to withstand larger relative angular deflections as well as the inherent shaking, vibrating, and rolling. Pipe connections must account for these movements in a gas sealing and relatively long-lived manner. Pipe connections of the prior art have not satisfactorily met these requirements.
This invention overcomes the problems of the prior art by providing a ball joint connection for interlockingly connecting lengths of exhaust pipe in a manner to allow substantial relative movement between the lengths of pipe in any angular or rotational direction. Moreover, the ball joint connection of this invention allows such relative movement while interconnecting the lengths of pipe in a long-lived and substantially gas leak-free manner.